Data from: Humans can use positive and negative spectrotemporal correlations to detect rising and falling pitch

To discern speech or appreciate music, the human auditory system detects
how pitch changes over time. However, the algorithms used to detect
changes in pitch, or pitch motion, are incompletely understood. Here,
using psychophysics, computational modeling, functional neuroimaging, and
analysis of recorded speech, we ask if humans can detect pitch motion
using computations analogous to those used by the visual system. We
adapted stimuli from studies of vision to create novel auditory correlated
noise stimuli that elicited robust pitch motion percepts. Crucially, these
stimuli are inharmonic and possess no long-range features across frequency
or time, but do possess positive or negative local spectrotemporal
correlations in intensity. In psychophysical experiments, we discovered
that humans can judge pitch direction based only on positive or negative
spectrotemporal intensity correlations. The key behavioral result—robust
sensitivity to the negative spectrotemporal correlations—is a direct
analogue of illusory “reverse-phi” motion in vision, and thus constitutes
a new auditory illusion. Our behavioral results and computational modeling
led us to hypothesize that human auditory processing may employ pitch
direction opponency. fMRI measurements in auditory cortex supported this
hypothesis. To link our psychophysical findings to real-world pitch
perception, we analyzed recordings of English and Mandarin speech and
found that pitch direction was robustly signaled by both positive and
negative spectrotemporal correlations, suggesting that sensitivity to both
types of correlations confers ecological benefits. Overall, this work
reveals how motion detection algorithms sensitive to local correlations
are deployed by the central nervous system across disparate modalities
(vision and audition) and dimensions (space and frequency).